It should survive as long as there are no predators in the tank. Wrasses will snack on them for sure, I'm suprised the trigger hasn't already. Best suggestion is find a different area in the tank where you can bury it's main body, either in the sand or placed gentley in a crevace. The tube will regrow if it's healthy enough. They move if pestered too often or they are not getting enough nutrient. Also be wary of peppermint shrimp, they can often pick at their tubes/crowns.
They need to be placed in a decent water flow area. Light is not a concern though. If the tank is quite young, you should consider using some live or frozen phytoplanton to augment it's feeding unless using blender mush.